title: CALLA negative precursor B lymphoblastic leukemia with MLL gene translocation and an unusual FISH signal pattern.
abstract: Rearrangements of the mixed lineage leukemia (MLL) gene at 11q23 commonly occur in infants with CALLA negative B lymphoblastic leukemia (B-ALL). Most often, these are detected by conventional karyotyping; however, fluorescent in-situ hybridization (FISH) with the help of a dual-color break-apart probe is used to identify cryptic translocations. When there is an MLL gene translocation, the usual FISH signal pattern is 1 red-1 green-1 yellow fusion signal pattern. We present a case of an infant with CALLA negative precursor B-ALL with a characteristic translocation t(4;11) (q21;q23), however, with an unusual MLL FISH signal pattern.
authors.affiliation: Department of Laboratory Medicine, Indo-American Cancer Institute and Research Centre, Hyderabad 500 034, India. nramana@yahoo.com
authors.forename: Sandhya G
authors.initials: SG
authors.lastname: Devi
authors.forename: Manu
authors.initials: M
authors.lastname: Goyal
authors.forename: N V S S
authors.initials: NV
authors.lastname: Ramakrishna
authors.forename: S Sudha
authors.initials: SS
authors.lastname: Murthy
mesh_terms: D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007223:Infant; D008297:Male; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000473:pathology*; D014178:Translocation, Genetic
chemical_list: C497422:KMT2A protein, human; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase